Abstract: A display system may include a light source that emits input light having a wavelength within a source wavelength range and an array of color conversion units overlapping a display area. A first set of color conversion units of the array of color conversion units may include a first color conversion medium that converts the input light to a first color of light having a wavelength within a first wavelength range that is different than the source wavelength range. The display system may also include a waveguide having an out-coupler that directs the input light from the light source toward the array of color conversion units. Various other devices, systems, and methods are also disclosed.

Abstract: Described are LED devices and corresponding manufacturing techniques. In some embodiments, an LED device includes a first doped semiconductor layer, a second doped semiconductor layer having an opposite doping, and a two-dimensional (2D) array of light emitting cells. Each light emitting cell corresponds to a mesa of an individual pixel and includes at least one quantum well. The 2D array is located between the first doped semiconductor layer and the second doped semiconductor layer. The LED device further includes a flattening layer between the first doped semiconductor layer and the 2D array. The flattening layer comprises an undoped quantum barrier (QB) layer that completely covers sidewalls of each light emitting cell in the 2D array. The undoped QB layer quantum mechanically isolates the light emitting cells from each other. The flattening or undoped QB layer may also protect the light emitting cells against etch-induced defects during a mesa pixelation process.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, one or more additional n-contacts are formed within the LED array. In some embodiments, the n-contacts may replace a pixel of the LED array. In other embodiments, one or more p-contacts of the LED array are resized or repositioned to accommodate the additional n-contacts without sacrificing pixels of the LED array.

Abstract: LED devices and corresponding techniques for manufacturing LED devices are described. In some embodiments, an LED device includes a plurality of mesas, each mesa corresponding to a separate LED and including a layered semiconductor structure. The layered semiconductor structure includes an active region and a quantum barrier (QB) layer. The active region has a matrix of quantum well (QW) cells that are quantum mechanically isolated by the QB layer. In particular, the QB layer can include ridge-shaped structures that laterally separate adjacent QW cells. The matrix of QW cells can be arranged as a two-dimensional array. In some embodiments, the QW cells are epitaxially grown such that each QW cell is thicker along a central region and thinner along a peripheral region, with the peripheral region corresponding to where the QW cell meets a ridge-shaped structure of the QB layer.

Abstract: A device includes an optical assembly and a digital projector. The optical assembly is configured to receive visible scene light at a backside of the optical assembly and to direct the visible scene light on an optical path toward an eyeward side. The optical assembly includes a dimming layer disposed on the optical path. The dimming layer includes a photochromic material that is configured to darken in response to exposure to a range of light wavelengths. The digital projector is disposed on the eyeward side of the optical assembly and is configured to selectively emit an activation light within the range of light wavelengths to activate a darkening of a region of the dimming layer to dim the visible scene light within the region.

Abstract: A micro-light emitting diode (micro-LED) includes a mesa structure that includes an n-type semiconductor layer, a p-type semiconductor layer, and an active region between the n-type semiconductor layer and the p-type semiconductor layer. The active region includes at least one quantum well layer. The at least one quantum well layer has a first effective bandgap and a first stress in a center region of the at least one quantum well layer, and a second effective bandgap and a second stress in a mesa sidewall region of the at least one quantum well layer. The second stress is lower than the first stress or is opposite to the first stress. The second effective bandgap is greater than the first effective bandgap to form a lateral carrier barrier in the at least one quantum well layer.

Abstract: A light source includes an epitaxial layer stack that includes an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer. The epitaxial layer stack includes a two-dimensional (2-D) array of mesa structures formed therein. The light source further includes an array of p-contacts electrically coupled to the p-type semiconductor layer of the 2-D array of mesa structures, a metal layer in regions surrounding individual mesa structures of the 2-D array of mesa structures, and a plurality of n-contacts coupling the metal layer to the n-type semiconductor layer at a plurality of locations between the individual mesa structures of the 2-D array of mesa structures.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, a current spreading layer having a conductive material (e.g., a conductive oxide) is formed on a surface of the substrate of the LED assembly. The current spreading layer may be a bulk layer or be patterned to increase light extraction from the LEDs of the array.

Abstract: In one embodiment, a computing system may receive a target color and a propagated error for a pixel location. The system may determine an error-modified target color for the pixel location based on the received target color and the propagated error. The system may identify, based on a location of the error-modified target color in a three-dimensional color space, a subset of pre-determined colors in the three-dimensional color space. The error-modified target color may correspond to a weighted combination of the subset of pre-determined colors. The system may determine a pixel color for the pixel location based on the subset of pre-determined colors and respective weights associated with the subset of pre-determined colors. The system may determine, based on the pixel color, driving signals for light-emitting elements associated with the pixel location. The system may output the driving signals to control the light-emitting elements associated with the pixel location.

Abstract: An optical assembly is configured to receive visible scene light at a backside of the optical assembly and to direct the visible scene light on an optical path toward the eyeward side. The optical assembly also includes a dimming layer disposed on the optical path, where the dimming layer includes a photochromic material that is configured to darken in response to exposure to a range of light wavelengths. An activation layer, included in the optical assembly, is also disposed on the optical path and includes an in-field dimmer. The in-field dimmer is configured to selectively emit an activation light within the range of light wavelengths to activate a darkening of a region of the dimming layer to dim the visible scene light within the region.

Abstract: In one embodiment, a computing system may receive a target color and a propagated error for a pixel location. The system may determine an error-modified target color for the pixel location based on the received target color and the propagated error. The system may identify, based on a location of the error-modified target color in a three-dimensional color space, a subset of pre-determined colors in the three-dimensional color space. The error-modified target color may correspond to a weighted combination of the subset of pre-determined colors. The system may determine a pixel color for the pixel location based on the subset of pre-determined colors and respective weights associated with the subset of pre-determined colors. The system may determine, based on the pixel color, driving signals for light-emitting elements associated with the pixel location. The system may output the driving signals to control the light-emitting elements associated with the pixel location.

Abstract: An optical assembly is configured to receive visible scene light at a backside of the optical assembly and to direct the visible scene light on an optical path toward the eyeward side. The optical assembly also includes a dimming layer disposed on the optical path, where the dimming layer includes a photochromic material that is configured to darken in response to exposure to a range of light wavelengths. An activation layer, included in the optical assembly, is also disposed on the optical path and includes an in-field dimmer. The in-field dimmer is configured to selectively emit an activation light within the range of light wavelengths to activate a darkening of a region of the dimming layer to dim the visible scene light within the region.

Abstract: A device includes an optical assembly and a digital projector. The optical assembly is configured to receive visible scene light at a backside of the optical assembly and to direct the visible scene light on an optical path toward an eyeward side. The optical assembly includes a dimming layer disposed on the optical path. The dimming layer includes a photochromic material that is configured to darken in response to exposure to a range of light wavelengths. The digital projector is disposed on the eyeward side of the optical assembly and is configured to selectively emit an activation light within the range of light wavelengths to activate a darkening of a region of the dimming layer to dim the visible scene light within the region.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, one or more additional n-contacts are formed within the LED array. In some embodiments, the n-contacts may replace a pixel of the LED array. In other embodiments, one or more p-contacts of the LED array are resized or repositioned to accommodate the additional n-contacts without sacrificing pixels of the LED array.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, a current spreading layer having a conductive material (e.g., a conductive oxide) is formed on a surface of the substrate of the LED assembly. The current spreading layer may be a bulk layer or be patterned to increase light extraction from the LEDs of the array.